Carburetor



J. T. RAUEN CARBURETOR Aug. 31, 1954 4 Sheets-Sheet 1 Filed Nov. 15. 1948 Aug. 31, 1954 J. T. RAUEN 2,687,710

C'ARBURETOR Filed NOV. 15, 1948 4 Sheets-Sheet 2 Aug. 31, 1954 J. T. RAUEN 2,687,710

CARBURETOR I Filed Nov. 15, 1948 4 Sheets-Sheet 3 INV T Aug. 31, 1954 I J. 1'. RAUEN 2,687,710

CARBURETOR Filed NOV. 15, 1948 4 Sheets-Sheet 4 INVENTOR.

Patented Aug. 31, 1954 CARBURETOR John T. Rauen, Detroit, Mich. Application November 15, 1948, Serial No. 59,997

This invention relates to carburetors and has particular reference to certain new and useful improvements in carburetors of the type commonly referred to as plain tube carburetors.

Principal objects of the invention are to provide:

A plain tube type of carburetor having means which will enable a cold engine to be started without the aid of a conventional choke;

A plain tube type of carburetor having means whereby a cold engine may be satisfactorily operated the instant immediately following cold starting and thence throughout the warming up period of the engine without the aid of a conventional choke;

A plain tube type of carburetor having means which will properly supply fuel to the engine from a single fuel feedin system and without the aid of a second fuel feeding system, such as those now employed and conventionally known as the idle or low speed system;

A plain tube type of carburetor having means for supplying fuel to the engine from a single fuel feeding system including a single nozzle at a rate sufiiciently uniform so as to enable the engine to idle smoothly;

A plain tube type of carburetor having a throttle constructed and arranged so that fuel can flow through the throttle, as distinguished from flowing over and around the throttle, for the purpose of obtaining smooth engine operation at idle and off idle speeds;

A. carburetor having means to prevent the pressure of backfiring from being transmitted through the fuel feeding system to the float chamber;

A carburetor having a thermostatic control for the fuel supplying means in which the thermothe intake system, of the en- 31 Claims. (01. 123-419) tremely cold engine;

A carburetor having means including fixed fuel and air jets to control the fuel required for all phases of engine operation and starting thereof; and

A new and improved carburetor which is simple in construction and more efficient and dependable in operation than carburetors of the type now available.

Other and further objects of the invention will be apparent from the following description and claims and willbe understood by reference to the accompanying drawings, of which there are four sheets which by way ofillustration showpreferred embodiments and the principles thereof and what I now consider to be the best mode in which I have contemplated applying those principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

Fig. 1 is a side elevational view of a plain tube type of carburetor embodyin the invention;

Fig. 2 is a side elevational view with parts broken away of the carburetor as shown in Fig. 1, looking at the left-hand side thereof;

Fig. 3 is a plan view of the carburetor with parts omitted;

Fig. 4is a sectional view taken along the line t l of Fig. 3, looking in the direction of the arrows;

Fig. 5 is a sectional view taken generally along the line 5-5 of Fig. 4, looking in the direction of the arrows, with certain parts shown in elevation;

Fig. 6 is a sectional view through the carburetor taken along the line ti-6 of Fig. 3, looking in the direction of the arrows;

Fig. '7 is a fragmentary sectional view taken along the line l-l' of Fig. 3;

Fig. 8 is a fragmentary sectional view taken along the line 8-8 of Fig. 4;

Fig. 9 is a fragmentary sectional view taken along the line 9-9 of Fig. l;

Fig. 10 is a plan view showing a modified. form of throttle valve;

Fig. 11 is a chart of curves showing the various fuel air mixture ratios which the carburetor herein disclosed will produce;

Fig. 12 is a schematic View illustrating a modified form of carburetor;

Fig. 13 is a schematic view showing a modification of Fig. 12; and

Fig. 14 is a fragmentary view showin the throttle stop mechanism in the cold idle position.

As illustrated in Figs. 1 to 10 of the drawings, a plain tube type of carburetor embodying the invention comprises in general a body 26 adapted to be mounted upon the manifold part 3.2 of the induction system of an internal combustion engine and having a main air passage it through which air flows into the induction system. A throttle Z is arranged in the air passage 2:1 so as to control the fiOW of air therethrough and is mounted on shaft 28 which is rotatably mounted in the body 26. The shaft 23 projects beyond the body it and has secured thereto a lever indicated generally at 30 forming part of a means by which the throttle may be opened or closed. The usual spring (not shown) biases closed position, as shown in Fig. 4.

The carburetor body provides a fuel reservoir 32 to which fuel is supplied through the fitting 3t and under the control of the float controlled valve indicated generally at 36. A fuel supplying system is provided for feeding fuel from the reservoir 32 to the main air passage 24, and this includes a fuel metering means indicated generally at 38, an accelerating pump indicated generally at 453, and a fuel nozzle 42 arranged in the air passage 24 upstream relative to the throttle 2'6 and to which nozzle 42 fuel is supplied from the reservoir by means of the pump to and under the control of the fuel metering means 38.

The air passage 24 includes a throat indicated generally at M which is arranged between the lines 46 and 8. A portion 50 of the wall of the air passage 24 defining the throat Ml projects inwardly so as to compensate for the displacement in the throat of the throttle shaft 28 and the nozzle 42 and the tube 52 so as to maintain substantially uniform velocity and pressure in the throat M; from one end thereof to the other.

The nozzle 62 includes a depending pen point shaped extension 5t which extends downwardly to and adjacent the throttle 25 in its closed position as shown in Fig. 4. The extension 54, is provided with a groove 56 through which liquid fuel can flow downwardly toward the end of the extension 54 and on to the throttle 26 without the uniformity of flow of such fuel being interrupted or disturbed. From the lower point of the extension 5 the liquid fuel flows on The throttle 26 is provided with a series of minute holes 58 of the order of 5 g of an inch in diameter. he fuel flowing on to the throttle 2'5 will tend to form a film across such holes 58, and the flow of air through such holes will carry the fuel with it and atomize it in the passage 24 below the throttle.

A modified form of throttle is shown in Fig. and consists of a valve member 358 provided by a body of a porous material, such as sintered metal, having mounting holes 366 for the screws which secure the throttle to the shaft 28. The porosity of the throttle 358 provides the same function in obtaining uniformity of fuel flow as do the holes 58 in the throttle 26 and also provides a degree of atomization verging on vaporization, which is an improvement over the specific form of the throttle indicated at 26. The porosity of the valve 358 should be such so as to be the equivalent to one A; inch diameter hole in the throttle. in a completely closed position, which setting will permit the starting of the engine when cold,

although the throttle 26 and the throttle 358 need not be completely closed for starting.

to the throttle 26.

the throttle to its The throttle 26 is shown in full lines This arrangement feeds small amounts of liquid fuel at closed throttle position to the engine uniformly in such a manner that the fuel will be atomized rather than be fed in drops which would tend to cause the engine to run roughly at idle speed.

The tube 52 is arranged in the throat M in line with and spaced from the end of the nozzle 42 and forms a leg of a lay-pass (it around the throttle 26 in its closed position, the other end of the by-pass terminating in a jet or orifice t2 which opens into the throat M just below the throttle 26 in its closed position. The by-pass (if! transmits the suction from the engine side of the throttle 26 when the same is closed to the end of the nozzle t2 so as to provide sufficient vacuum at the end of the nozzle 2 to obtain the flow from the nozzle of the required amount of fuel for operating the engine at idle and off idle positions of the throttle.

The passages t l extending between the bypass 5% and the throat 44 provide a graduation of the vacuum produced at the end of the nozzle if by the bypass as the throttle is is moved from its closed toward its open position. The dotted line position of the throttle 2.6 as indicated in Fig. l indicates the normal hot idle position of the throttle 26. At idle engine speed, and the first portion of off idle engine speed, air mostly flows through loy-pass fill, entering at openings to and at one end of tube 52.

Almost all of the very small amount of fuel flowing during the above stated engine speeds, does so in a small liquid stream through nozzle 42 passage, to the groove 56, which by capillary action draws the fuel downwardly onto the throttle valve 25 where air passing through the valve 2E3 carries the fuel with it at a steady speed into an atomized state upon emersion from the throttle valve at the low pressure side thereof.

The groove 55 prevents what would otherwise be a natural globular fuel formation at the end of nozzle 42, which formation causes the fuel flow speed to vary, resulting in irregular, rough, engine operation at idle and off idle speeds up to where energetic atomization takes place at the end of nozzle 42.

At engine speeds in excess of the above stated idle speed, increasing portions of the total fuel flowing, passes through the by-pass Eli, and emerges, in a well atomized state, from openings 54-, in addition to opening 52, as the throttle position exposes openings B l to the low pressure side of the throttle valve 25.

At engine speeds in excess of such speed where the vacuum set up in the throat 44 by the air speeding to the engine through the air passage 24, balances the vacuum under the throttle valve 26, to which openings 62 and 64 and the bypass 69 are subjected, the liquid fuel stream previously emitted from the nozzle 42 is converted into an atomized state, and atomized fuel is then emitted from all mentioned outlets.

This last mentioned state of fuel flow occurs with all engine speeds associated with full open throttle engine operation, except, the very lowest engine speed where liquid fuel could again emerge from nozzle 42.

The entire fuel track, from the top of standpipe 80, is so constructed that globular fuel formation does not occur even at the recess fill in the fuel track, after the fuel has once filled this recess.

Feeding fuel to, and through, the throttle in 80 into the chamber 78.

the above stated manner provides also, less carburetion noise about the engine.

The float controlled valve 36 may be of conventional construction and includes the movable valve member 66 which is adapted to be seated by a wire bracket 68 when the fuel in the reservoir attains the level indicated at 10. The bracket 68 is generally of C-shape, and the ends are pivoted as indicated at I2, the intermediate parts of the bracket 68 being secured to the floats 14 disposed in the reservoir or bowl 32. The floats T4 are relatively shallow and of large cross section so as to be sensitive to the level of fuel in the bowl 32 and thereby control the fuel level I within close limits.

The fuel metering means 38 is constructed and arranged to meter the flow of fuel from the bowl 32 to the air, passage 24 in response to the suction therein. The nozzle 42 is formed at one end of a passage I6, the other end of which communicates with a chamber 18. A standpipe 00 is seated in the chamber 18 and projects up wardly above the fuel level in the bowl 32 for a distance which, is sufiicient to prevent fuel from flowing out of the bowl 32 into the passage 16 due to normal tilting of the car in which the carburetor may be mounted.

The upper end of the. chamber I8 is formed by a hollow tubular member 82 into which the upper open end of the pipe 80 projects. There is sufiicient clearance between the upper end of the pipe 80 and the lower end of the tubular member 82 to permit a free flow of fuel therebetween. However, the upper end of the pipe 80 is so disposed. with respect to the lower end of the passage 84 that the air which flows into the tubular member 82 through the passae 84 and into the space between the upper end of the pipe 80 and the lower end of the tubular member 82 will wipe liquid fuel off the upper end of the tube so as to expedite the flow of fuel from the tube This action is of particular significance at idling speed of the engine.

The passage 84 at its upper end terminates in an orifice which forms a valve member 86 through which air flows into the chamber I8 of the fuel metering system 38. The flow of air through the valve member 86 is regulated or metered by the valve member 88 which as i1- lustrated includes an annular portion that seats upon the valve member 86 and a depending tapering pin 80 that projects downwardly through the passage 94. It should be noted that the passage. 84 at its upper end is of uniform cross section for a short distance, and therebelow tapers outwardly away from the pin 90 which tapers inwardly.

The valve 88, 86, hereinafter designated as an air metering valve, as illustrated herein is closed during the cranking of the engine to start the same and is controlled so as to. open as soon as the engine fires, and such valve 88, 36 as disclosed herein is at least partly open at all times during operation of the engine. would be possible, however, to so arrange the valve 88, 86 that it may be open slightly during cranking of the engine.

The lower end of the pipe 80 communicates with a valve chamber 92 which is in communication with the bowl 32 through passages 94 whereby fuel is supplied to the valve chamber 92 and the interior of the pipe 80, and fuel will stand in the pipe 80 at the same level that it stands in the bowl 32 when the engine is not operating.

The pin 90 may be formed as part of a rod 96 which extends downwardly through the tube 80 and the valve chamber 92 into a guide formed below the valve chamber 92. Within the valve chamber 92 the rod 96 is provided with a valve member 98 which together with the lower end of the pipe forms a liquid fuel metering valve for regulating or metering the flow of liquid fuel from the bowl 32 upwardly through the pipe 80. The valve member 98 moves with the valve member 88, and as illustrated the valve member 98 will cooperate with the lower end of pipe 80 to restrict the flow of fuel upwardly into the pipe 80 upon opening movement of the valve member 63 after the valve member 88 has opened a certain amount following the starting'of the engine.

The height of the fuel level 10, the distance that the pipe 80 projects above the fuel level I0, the liquid fuel metering valve 98, and the valve orifice which it controls, and the air metering valve 86, 88 form the variables by which fuel and air mixture ratios are controlled.

With the parts of the fuel metering means 38 arranged as illustrated in Fig. 4 and with the throttle 26 set as illustrated in full lines, cranking of the engine will create suflicient vacuum at the end of the nozzle 42 to produce sufficient fuel flow to enable a cold engine to be started, and at the same time the setting of the throttle 26 is such as to obtain vaporization of fuel. within the passage 24 below the throttle in order to enable the engine to start. As soon as the engine starts to fire, mechanism hereinafter described will open the valve 88, 86 to a position to provide continuous running of the engine thereafter.

In order to prevent pressure in the passageway 24, such for example as that due to 'backfiring,

from being transmitted back through the nozzle 42 and passage 16 into the fuel reservoir there is provided a pressure responsive valve which includes the ball valve member I00 which during normal operation is seated in a recess I0! communicating with and below the passage 16.. The recess is provided with a port I02 which communicates with the throat or venturi 44 of the air passage, and the ball valve member I00 normally is seated so as to close the port I 02. However, sudden increase in pressure in the passage will lift the ball valve member I00 and position it so as to obstruct the orifice I04 thereby effectively to prevent the transmission of pressure back through the fuel metering means 3% into the carburetor bowl 32.

The air metering valve 86, 88 and other working parts of the carburetor are enclosed by up standing walls provided on one of the members 20 of the carburetor and a removable cover I06. In order to get air into the space below the cover I06 there is provided an air passage I08 which opens into the upper part of the carburetor bowl and an opening H0 in the wall I I2 which closes the top of the bowl 32.

The carburetor also is provided with an accelerating pump indicated generally at 40 which is arranged to be actuated by opening movement of the throttle. The pump 40 includes a cylinder I I4 which is arranged to draw fuel from the bowl 32 through passages H6 (Fig. 8), H8 and I29, and past check valve I22 which is arranged to close the passage I20 upon the delivery stroke of. the piston so that upon the delivery stroke ofthe piston some of the fuel inthe cylinder will by-pass the head I28. A piston member I32 freely 'slidable on the rod its is adapted under theinfluence of gravity after the downward stroke of the head I28 to displace such by-passed fuel past the head I28 so as to thereby provide for delivery of fuel from the accelerating pump 50 after the delivery stroke of the head l28.

Fuel is delivered from the cylinder I M through passage its and past che l; valve I33 into the chamber 28, and thence through the passage ES to the nozzle 42. The piston rod its is adapted to be reciprocated by a crank indicated generally at I iil, one end Hi2 of the crank extending through the rod I30 and the other end I i l of the crank being pivoted in the bearing Hit. A rod its pivotally connected at one end to an arm I55 of the throttle lever to is pivotally connected at its other end to the crank Hit so that upon opening movement of the throttle the accelerating pump id will be actuated to supply fuel to the nozzle E2 in addition to that supplied thereto through the fuel metering means 2-8.

The fuel metering means 38 is controlled by re temperature condition of the engine, and to this end there is provided a thermostat or thermally responsive element use which is disposed on a plate I62, the plate '22 closing the top of a passage its which is in communication with the interior of the engine exhaust passage forming the hot spot of manifold 22. The thermostat Hit is enclosed in a housing which forms a guide for one end of thermostat rod I66. Thermostat rod ass is further supported for sliding movement in a guide Vii, and above the guide the thermostat rod extends laterally through guide I12, and the end li t of the thermostat rod extends below a lever I16.

The lever Ilb is pivotally supported on a pin illl which is supported by upstanding brackets i853 and F62. The leve H6 is provided with a laterally extending arm I365 which projects below a collar ids secured on the upper part Ifiil of valve member 88. The part I96 is slidably arranged in a guide V32 formed by a hole in a bracket ass. The bracket 59 i is secured by screw I96 on the top of bracket or post I82. The lever I'M is provided with two screws 2% and 282, the lower ends of the screws projecting below the lever lit for engagement with the end are of the thermostat rod. The screw 20!! is designated for convenience as the hot idle mixture adjusting screw and is arranged to cooperate with the end PM so as to determine the hot idle position of the air metering valve member 88. The screw 202 is the cold idle mixture adjusting screw and cooperates with the end of the thermostat rod I14 to determine the cold idle position of the air metering valve member 88.

The collar IBG on the upper part I96 of the air metering valve member 88 is above the arm we on the lever lit, and the elevation of the lever H6 is determined by either the screw 206) or the screw 282 and the elevation of the end He of the thermostat rodv As shown in Fig. a, the parts of the carburetor are arranged for starting a cold engine and the thermostat see is cold and in its contracted condition. As the thermostat We is heated up due to the absorption of heat from the manifold 22 and the engine, it expands and the upper arm of the thermostat Iiit will react against the lower end of the thermostat rod I66 and push the rod of the thermostat rod upwardly, whereupon the other thermostat rod will by reacting on the lower end of the screw 202 lift the lever I16 and the air metering valve 88 so as to open the air metering valve and permit the flow of air into the passageway 84. As the valve member 88 is elevated, the valve seat or orifice 8% will be opened and the size of the orifice will increase as the valve member 88 moves upwardly.

It will be observed that the end I 'l of the thermostat rod has a slight downward slope toward the right-hand side after a certain amount of upward movement of the end I'M of the thermostat rod the lower end of the screw 220 will engage the end I'M of the thermostat rod while the screw 262 will be moved out of contact with the thermostat rod upon upward movement of the lever Ht. Thus, when the engine is cold the screw 2&2 will by cooperation with the end 11s of the thermostat rod determine the position of the air metering valve member 88, while when the engine is hot the screw 285 will by cooperation with the end I14 of the thermostat rod determine the position of the air metering valve member I38.

The fuel metering means 33 are also controlled to some extent by the throttle 2E, and to this end the thermostat rod I65 has secured thereto an arm 2H), the arm 2m being provided with a finger 2 i2 which is in engagement with an edge of a sector 215 formed as a part of the throttle lever 32. The edge of the sector 2% includes portions 256, 2H, H8, 220, 224 and 228 which cooperate with the finger 212, so as to shift the thermostat rod and thereby, through the mechanism previously described, shift or permit the shifting of the air metering valve member 88 of the fuel metering means 38, or to limit the opening movement of the throttle.

The throttle lever 32 includes an arm 232 to which the accelerator pedal may be connected for imparting movement to the throttle lever 30 so as to open the throttle 26. The throttle lever Bil also includes an arm 23 carrying an adjusting screw 23B threadedly mounted thereon, the end of the screw projecting to the left of the arm 234 (Fig. 1) being engageable with the lower end 231 of a throttle rod 238 so as to determine the position to which the throttle will close under the influence of the usual spring. The spring shown around the shank of the screw 2535 functions to hold the screw in the position as adjusted, the head of the screw 23% having the usual slot for receiving a screwdriver so that the closing position of the throttle 26 may be adjusted.

The carburetor body is provided with a boss 2453 against which the lower end 23? of the throttle rod abuts so that the throttle adjusting screw 23% will clamp the lower end 23? of the throttle rod between the end of the screw 23% and the boss 2M3. The throttle rod 238 extends through a hole in the arm 25% and is slidably mounted in a guide 242 provided by the body of the carburetor. The upper end of the throttle rod 238 above the guide 2&2 projects through a slot 2G5 in a piston member 2% (Figs. 3 and '7) The end 2% of the throttle rod extending into the slot in the piston is provided with a hole through which one end of a spring 248 extends. The slot in the piston 244 through which the end 2% of the throttle rod projects extends downwardly from the top of the piston 22% to a point somewhat above the middle of the height thereof. The piston 224 is biased upwardly by a spring end I'M of the thereof (Fig. 5), and

251]. The lower end of the piston is in communication with the air passage 24 below the throat piston 244.

The spring 248 has its lower end turned laterally so that of the throttle rod when the spring 248 is pulled upwardly, it being noted that the spring 248 can move to a certain extent relative to the end 246 of the throttle rod and vice versa. The upper end of the spring 248 is secured to the thermostat rod I66, and when the thermostat rod I66 moves upwardly it will under certain circumstances exert an upward tension on the end 246 of the throttle rod for lifting the throttle rod 238. The lower end of the throttle rod 238is illustrated in Fig. 1 in the hot idle position and is clamped between the boss 24!] and the end of the screw 236. by the usual throttle closing spring.

With the parts arranged as shown in Figs. 1 and 7, opening movement of the throttle lever 30 will release the throttle rod 238 and permit the same to drop until the end 246 of the throttle rod hits the lower end of the slot 245 in the piston. This will bring the notch 260 (Fig. 14) into alignment with the end of the screw 236, and if the throttle 26 is allowed of the slot 245 in the piston is heavy, horizontally extending or the lower end of the slot 245, and the lower end is greater If the throttle is with the screw 236, prevent the throttle lever 30 from returning to the positions indicated in Fig. 4. This will provide a fast idle for cold engine operation.

When the thermostat rod I66 moves upwardly it will, through the spring 246, lift the end 246 of thethrottle rod 238 so as to position the throttle rod in its hot idle position as shown in Fig. 1.

Opening movement of the throttle lever 30 with the parts arranged as shown in Fig. 1 will effect opening movement of the air metering valve 88, 86. The finger 2|2 as shown in Fig. 1 is in engagement with the edge portion 216 of the throttle lever 36. Opening movement of the throttle lever 30 will move the throttle lever 30 and the throttle shaft 28 clockwise, and during such movement the finger 2 I2 will be moved upwardly. when it is engaged by the cam edge portion 2!! of the lever 30, and further clockwise.

throttle lever 36 will bring the below the finger 2E2, thereby 212. Such elevation of the finger 2|2 will lift the thermostat rod I66 and through it the air metering valve member 88, as previously described, in order to open the air metering valve 36, 88 of the fuel. metering means 38.

Since the full suction at the nozzle 4-2 is transmitted to the fuel in the pipe of the fuel metering means when the valve 86, S8 is closed,it will be apparent that a rich mixture is provided for starting a cold engine. However, as soon as the valve member 88 moves upwardly to open the air metering valve, air will be metered into the passageway 84 which will reduce the suction movement of the edge portion 2| 8 raising the finger and this movement of the air meterin response to opening movement of the throttle will change the mixture from that required to start a cold engine to that required for operating a cold engine.

The length of the edge portion 2 i 8 of the throttle lever 30 and with the range of throttle opening required for operating a cold engine, the right-hand end of the edge portion positioning the finger 2 2 higher than the left-hand end of such edge portion. The right-hand end of the edge portion 2|8 immediately adjacent the cam 2!! will position the air metering valve member 88 so as to provide a fuel mixture for operating a cold engine at idling speeds. Further opening movement of the throttle lever 36 to bring the left-hand end of the edge portion 2; below the finger 2 [2 will permit a small amount of closing metering valve member 88 ture for operating a cold idle.

The portion 226 of the-throttle lever functions as a stop to limit opening movement of the throttle when the engine is cold, and will upon engagement with the finger 2| 2 prevent further opening movement of the throttle. However, the positioning of the finger 212 by the edge portion 2 l8 will position the air metering valve member 88 to provide for a full power mixture for the engine when cold when the portion 220 is in the path of movement of the finger 2 I 2. If the throttle lever is permitted to move toward the: closed engine at speeds above position of the throttle when the engine is cold,

the pin 236 will engage the throttle rod 238 above the notch 266 so as to keep the finger M2 on the right-hand end of the edge portion 218 of the throttle lever so as to position the metering valve member 88 in order to provide a mixture for operating a cold engine at idle speed.

As the thermostat rod I66 is moved upwardly by the thermostat I60 so as to open the air metering valve 88, 86 as the engine warms up, the richness of the mixture supplied by the fuel metering means 38 will be reduced and the finger 2l2 will be lifted to a position above the path of movement of the stop 220, thereby permitting full open position of the throttle when the engine is hot. The edge 224 of the throttle lever 36 is engageable with the finger 2I2 so as to function as a stop to limit opening movement of the throttle 26 when the engine is hot. When the engine is hot the finger 2l2 will cooperate with the cam surface 228 to partly close the air metering valve member 88 so as to provide a richer mixture for the engine at full open throttle or the position thereof correspond 11 full power than is provided for engine operating conditions less than full power or full open throttle.

In other words, after the engine is warmed up, the thermostat It!) and the thermostat rod I66 position the air metering valve so as to provide an economy mixture for hot engine operation, and when full power operation is desired the earn 223 will reduce the air orifice opening of the air metering valve 88, 88 so as to provide a richer mixture for full power hot operation than is provided for hot economy operation.

Fig. 12 is a schematic view of another form of plain tube type of carburetor embodying the invention. As therein shown, the main air passage 4% forms a venturi of which 401 is the throat. The high speed nozzle 4432 ends in the throat 40! and contains an air bleed 483. of the nozzle 4&2 is provided with an economy fuel supply jet 494 and a full power hot jet 4&5 under the control of a valve 406 (shown closed). The low speed or idle system fuel jet 4 31 is also arranged to feed fuel from the nozzle 482 into the idle system, and the idle system further includes an air bleed 408. The nozzle M32 is provided with a valve 499 which controls the flow of fuel into the nozzle 402 during warm-up operation of the engine. The idle system is also provided with a valve 4H3 (shown open) which controls or regulates the flow of fuel into the idle system during cold starting and warm-up. The idle system delivers fuel in a conventional manner into passage 40% adjacent throttle M l.

The throttle M l is provided with an operating lever similar to lever 30 to which the conventional control rods (not shown) are attached. The lever tea has a pivotal connection with one end of rod 412. The lever 500' includes cams M3 and M4 and an interval arm or lever M5 which is engageable with a stop 4:5 so as to provide a stop to determine the cold starting position or the throttle M l. A vacuum partially actuates a lever 4 l 8 pivoted at 4 i 9 adapted to engage the rod M2 to position the throttle M1 in its cold idling position. Rod 412 also cooperates with lever M8 to limit the cold full open position of throttle 4H, the same as stop 228 in Fig. l. The hot full open stop, not shown, for throttle 4H being also similar to stop 224, Fig. 1.

A lever 42s pivoted at 421 is adapted to follow the cams M3 and 4&4 during movement of the throttle tit and is connected to a rod 422 which in turn is connected to lever 423. Lever 423 is pivoted 45:4 and connected to rod 425 in turn connected to lever 425. Lever 426 is pivotally connected at 4-2! to lever 428 which is pivotally mounted at 42% and connected to the rod 430 which engages the thermostat 34L The lever 42s is also engageable with the lever M8 for actuating the same to disengage the rod M2 when the engine is hot for allowing the throttle to return to its hot idle position as regulated by the lever 43: pivoted at 432.

Motion of lever etl is limited by arms 431 and 438 and is adapted to engage the throttle lever ME: to hold the same away from stop MB A spring 32 1 yieldingly connects lever 43l and lever 428 whereby the lever 43! is moved out of the path of the throttle during cold starting and warm-up operation of the engine.

The lever 42% through its arm 433 is adapted to engage the head of the valve 4H], and arm 434 of lever @233 is adapted to engage the head of valve its and is pivotally connected to the operating shaft of valve 4%. Spring 435 biases the The opposite end operated piston 4H wardly. The rods scribed, and to .12 vacuum operated piston ill' upwardly. A lost motion connection 436 permits the piston 4!! to move without correspoding movement of the lever 8 when the lever M8 is overruled by the lever 42%.

Preparations for starting a. cold, engine As the engine cools from normal hot, the thermostat 34! allows the rod 4st to move down- 422 and 43d tend to gravitate downwardly as indicated by weights Frill and 502. This action of rod 43!! rotates the lever 428 counterclockwise and raises the fulcrum 421 carrying the lever 426, which causes a slight clockwise rotation of the lever 426 about its connection with the valve 4%. Such slight rotation of the lever 426 plus the raising of fulcrum 421 causes the arm 433 of the lever 426 to engage the head of the valve Mil and raise it to fully open the fuel passage to the idle system and simultaneously nearly engaging the head of valve 409, the valve 4% remaining closed because its head forms a pivot for the slight rotation of the lever 425.

Rotation of lever 42s disengages lever 41B, allowing the lever 4|8 to fall upon the piston 4H and simultaneously stretching the spring 324 to urge the lever 43! upwardly. As the lever 43! is at such time engaged by the throttle lever 4l5, it will not move until the throttle lever has been manually opened slightly. After such throttle action the lever 43M is out of the path of throttle lever 455, and throttle lever M5 will then stop against ilt. Simultaneously with the Slight clockwise rotation of lever 426, motion is transmitted through rod 425 andbell crank lever 423 and rod 422 to lever 420, allowing lever 42:! to be engaged by cam M3 which it had been raised clear of during hot engine operation hereinafter described. The carburetor is now adjusted ready to start a cold engine.

Starting a cold engine cranking of the ventional electric starter with the throttle positioned as regulated by the stop 4H5 creates sufficient vacuum on the engine side of the throttle 4! I to draw through the open valve 4ll! suflicient additional fuel to enable the engine to start practically instantly, and also substantially instantly to vaporize at least part of the fuel which is discharged into the passage 400 by the jet 504 to which fuel is supplied under control of the valve 410, and by the normal idling system.

Upon firing of the engine, the throttle MI is manually opened, at least far enough to allow the rod 4 l2 to be engaged by the lever 4 l 8, whereupon the throttle M I is positioned partly open to supply to the engine a mixture which will sustain the engine in continuous operation at cold idle speed.

The aforementioned operation of the engine creates a vacuum in the induction system in an amount of the order of 18 inches of mercury approximately, more than sufficient to actuate the piston 4!? against the spring 43%, the spring 435 having a strength sufficient to oppose movement of the piston 41'! until a vacuum of about 4 inches of mercury exists in the induction system, which occurs at full open throttle operation. The underside of the piston 4H on which the spring 435 bears is in communication with the passage 40!) on the downstream side of the throttle. Movement of the piston 4H as described allows the levers 4'32 and 458 to engage as previously dedisengage should the engine be stopped while still in the cold condition, and

engine by means of the conl the venturi 40 cam 4ft directly under lever 420 and thereby transmits motion through lever 420, rod 422, lever 426, and rod 425 to lever 426 with the effect of. closing the valve 4|0 to lessen the amount of fuel allowed to. flow to the engine to a degree which properly supports warming up operation of the engine. The valve M is thereafter gradually fully closed by heating up of the thermostat 34| as warming up proceeds to completion in a manner the reverse of the action as previously described. I

Simultaneously with the foregoing described rotation of lever 426, the valve 406 is opened to allow fuel to flow through the jet 405 into the nozzle 402 to provide fuel in addition to the amount always supplied this occurs only after the throttle 4 is opened in excess of about one-fourth of its total open ing movement. With the jets 404 and 405 open,

fuel required for ooldoperation of the engine is provided while the throttle is open to an amount less than the angular position of the cam 4|4 which is about one-third to one-half of throttle opening. l

Simultaneously with the above described rotation of lever 426, the arm 434 of lever 426 engages the head of valve 409 but does not open the valve. The jet 405 controls the quantity of fuel entering the nozzle 402, regardless of the extent to which valve 406 is opened in excess I of that to which thejet 405 will pass fuel.

At the completion of thewarm up under conditions as described, the lever 43| is hung upon the lever MS of the throttle, and rod M2 and lever 4 l8 are still engaged. Slight opening movement of thethrottle disengages the rod 4|2 from. the lever M8 and allows the thermostat to move the lever 4|8 away from further engagement with rod M2, and the lost motion connection 436 allows the piston 4|! to move its full amount without correspondingmotion oflever 4|8. At the same time the lever 43| is allowed to fall into the path of the throttle lever 4|5, adjusting the throttle 4|! to the normal hot idle position. The thermostat is allowed to complete its motion to the extent of lowering the fulcrum 421 of lever 426 to a point where rotation of lever 426 will no longer actuate the valves4l0 and 403, and simultaneously pivoting lever 426 about the valve 466 raises 420 and 422 to clear the cam 4|3 but still allowing the cam M4 to engage the lever 420 for future actuation of valve 406.

Operation daring driving of the vehicle immediately following 802d starting The same actions of the carburetor controls, including the thermostat 34|, take place during this phase of engine operation. A substantial portion of throttle opening movement is required before the cam 4|4 engages the lever 420. Meanwhile the delivery of fuel from the idle system and through the valve 4| 0 has ceased because the throttle 4 when opened beyond cold idle position gradually renders the idle system ineffective. The increased volume of air associated with such gradual opening of the throttle 4| I gradually increases the quantity of air passing through and in consequence the quantity through the jet 404, and

a cold engine.

transmitted to lever 426 and thereby further lifts the valve 406 but causing no additional quantity of fuel to pass through jet 405. This further opening movement of the throttle also opens the valve 409, allowing additional fuel into the nozzle 402 to support cold, full power operation of a cold engine. Simultaneously the valve 4H0 is closed. Simultaneous with full opening of the throttle the vacuum on the engine side of the throttle is reduced and the spring 435 raises the piston 4|! and the lever 4|8 out of the path of the rod 4 l2. As the throttle is closed, an inverse actuation of the foregoing members occurs in order to properly position the throttle at its cold idle position.

Normal hot operation At the completion of the engine warm up the lever M0 is moved out of the path of the rod M2 and the lever 43I into the path to the throttle, and thereafter the throttle is positioned to the idle position thereof for normal hot engine operation. The lever 42a is raised so that it no longer engages the cam 4|3 but only the cam M4. The fulcrum 421 of lever 426 is lowered to where the valves 406, 409 and 4|0 are fully closed and only the fuel feeding jets 404 and 467 remain open. Rotary motion of lever 426 during normal hot operation originates from the cam M4 and the throttle 4| I, and the arm 433 merely moves away from the head of valve 4|0 while the. arm 434 of lever 426 raises the valve 406 sufficient for full fuel flow through the nozzle 402 as governed by the jet 405 while the valve 409 is retained closed since the fulcrum 42'! is lowered allow the above described action valve 406 without opening the valve 400.

In the modification shown in Fig. 13 the piston 4|! alone actuates the valve 406, and the arm 434 of lever 426 isnot used to operate the valve 406 but only the valve 469 which in such arrangement would be lifted during cold starting of the. engine prior to the opening of valve 406 as described. The operation of valve 466 by piston 4|l takes place at any time that the vacuum on the engine side of the throttle 4| falls below say four inches of mercury, and irrespective of the position of the throttle or the speed of the engine. Thus the valve 466 will be open during both cold and hot engine starting and closed immediately upon starting of the engine, providing the throttle valve 4 is positioned as illustrated and described during engine starting. The action of valve 406 as just described in no way interferes with the engine starting operations. The construction and operation of the modification illustrated in Fig. 13 is otherwise the same as that shown in Fig. 12.

Fig. 11 is a chart of of curves which graphically illustrates the relative values of various fuel curves and various pressures in the induction system relevant to carburetor operation obtainable with carburetor disclosed in Figs. 1 to 1G. The curve marked A is a curve showing the fuel air mixture ratio for starting and operating The peak of hump. portion Al. of curve A shows the air fuel mixture ratio during the crankingof the engine. The air fuel mixture ratio curve for wide open throttle opthrottle.

eration of a cold engine at full power follows the line A2 instead of hump Al.

The curve marked B indicates the vacuum produced by the fuel nozzle within the fuel metering system with the air metering valve 83, 86 open for cold operation of the engine. The curve marked indicates the vacuum within the metering system during cold operation with the air metering valve 8%, so open for cold operation of the engine, and due to the passagefifl and the angular position of the throttle. fhe curve marked D is the curve showing the fuel air mixture ratio for full open throttle operation of the engine when hot, and the curve marked E is the curve showing the vacuum within the metering system when the valve 89, 86 is open for hot operation of the engine. Curve F indicates the vacuum in the manifold during wide open throttle operation between zero and maximum air quantity. J is the curve showing manifold vacuum during progressive opening of the throttle from zero to maximum air quantity. The curve marked G is the hot economy fuel air mixture curve, the peal; of the hump portion thereof indicating the hot idle portion of such curve, and the downwardly sloping portion between the peak and the level part of the curve indicating the fuel l'llXl'llll'e curve at on idle positionsof the The dotted portion C indicates the shape that the economy curve would have if the es omitted, and the curve H is a curve showing the vacuum within the metering system during normal hot operation due to the passage to and the angular position of the throttle and the open position of metering valve 88, 86. The E curve and the H curve combine to produce the hump portion of curve G, and the B curve and the C curve combine to produce the hump portion AI of curve A. The line K indicates a point relative to zero and maximum air quantity at which the effects of passage 60 ceases to influence the vacuum at the end of nozzle #42 and its corresponding effect upon the shape of curves A, D and G. Substantially similar curves would be obtained from the carburetors shown the modified figures. These curves indicate that the cold operating air fuel mixture curve is richer than the hot full power curve, and that the hot full power curve is richer than the hot economy curve.

Certain subject matter disclosed herein is disclosed and claimed in my prior copending application Serial No. 360,046, filed October 7, 1940, for Carburetors, now patent No. 2,453,728, issued November 18, 1948, and of which the present application is a continuation in part.

While I have illustrated and described pres ferred embodiments of my invention, it is understood that these are capable of modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within .19 purview of the following claims.

I claim:

1. In a carburetor for supplying air and fuel to the induction system of an internal combustion engine in response to the absolute air pressure therein, an air passage of predetermined length, and open at both ends thereof, one end being adapted for communication with said induction system and the other end open to the atmosphere, said air passage also being so constructed and arranged throughout a portion of its length whereby air entering one end of said air passage at a given absolute air pressure, en-

route to the opposite end of said passage, is sub jected to absolute pressure changes as the air approaches, and leaves, said portion, a throttle valve, operably disposed in said portion for varying the said absolute air pressure in said portion and for regulating the flow of air and fuel through said portion and said air passage, to said induction system, fuel supplying means for delivering fuel into said air passage and having at least one fuel outlet disposed in said portion upstream, relative to said throttle, absolute pressure transmitting means for conveying the absolute air pressure occurring at one side of said throttle, when said throttle is less than full open, to the other side of said throttle, adjacent said fuel outlet in said fuel supplying means, both ends of said absolute pressure transmitting means terminating in said portion, said portion being adapted to maintain said sure substantially constant length of said portion at least during such conditions as are associated with full open throttle.

2. A plain tube type of carburetor for supplying fuel to the induction system of an internal combustion engine comprising an air passageway, a throttle in said passageway operable for regulating the flow of air and fuel through said passageway into the induction system, means for delivering fuel to said air passageway in response to suction therein, air metering means operable for supplying and controlling the supply of air to said fuel delivering means for regulating the supply of fuel therethrough to said air passagethroughout the way, means operable inresponse to the tempera ture condition of the engine for regulating said air metering means so as to decrease the richness of the mixture supplied to said fuel delivering means as the engine warms up, and means responsive to partial opening movement of the throttle for adjusting said air metering means so as to decrease the richness of the mixture supplied through said fuel delivering means upon opening movement of the throttle when the engine is cold.

3. In a carburetor for supplying fuel to the induction system of an internal combustion engine, a passageway through which air and fuel flow to the induction system, a throttle valve operable for regulating the flow of fuel and air through said passageway into the induction system, means for supplying fuel to said air passageway, and means operable in accordance with the temperature condition of the engine for positioning said throttle in a position closed beyond the normal hot idle position of the throttle for cold starting whereby a high vacuum in the induction system may be obtained for quick starting of a cold engine.

4. In a plain tube type of carburetor for supplying fuel to the induction system of an internal, combustion engine, a passageway through which air and fuel flow into the induction system having a throttle therein for controlling the flow of fuel and air to the induction system of the engine, means including a nozzle for delivering fuel to said passageway, fuel metering means for controlling the supply of fuel to said nozzle through said fuel delivering means, and means operable in response to the positioning of the throttle, the temperature condition of the engine, and the vacuum in the induction system downstream of said throttle for controlling said fuel metering means so that fuel is supplied to said engine through said passageway in accordance with the requirements of the engine.

absolute air pres 5. In a carburetor for supplying fuel to the whereby said fuel metering means as adjusted induction system of an internal combustion enby said actuating means remains so adjusted durgine, an air passage through which air and fuel ing substantial movements of said suction reguflOWs to said induction system, a throttle valve lating means, and means limiting the adjustoperably disposed in said passage for regulating ment of said metering means by said other means. the flow of fuel and air therethrough enroute to 8. In a carburetor for supplying fuel to the said induction system, fuel delivering means induction system of an internal combustion enadapted to supply fuel into said passage, fuel gine, an air passageway through which air flows metering means operably disposed in said fuel into said induction system, a throttle in said air delivering means and adapted to regulate the passageway for regulating the flow of air and flow of fuel through said fuel delivering means fuel through said air passageway into the inducto suit the operating condition of said engine tion system, means for supplying fuel to said air as related to quantities of fuel supplied to said passageway including amain fuel nozzle arranged engine, when said engine is less than normal hot, to discharge fuel into said air passageway upthe same said fuel metering means also being stream relative to said throttle, said nozzle having adapted to regulate the flow of fuel through said a fuel conveying extension projecting toward and conveying means to suit the operating conditions in close proximity, to said throttle and adapted of said engine as related to quantities of fuelsupto convey a continuous stream of liquid fuel from plied to said engine when said engine is normal said nozzle to said throttle, and a by-pass for hot, operating means associated with said fuel transmitting vacuum from the downstream side metering means, and operable in part responsive of said throttle to said nozzle for effecting the to movements of said throttle for regulating said delivery of fuel to said fuel conveying extension fuel metering means to change the said fuel flow of said nozzle when said throttle is closed beyond as compatible with either of said engine operat a predetermined position during both hot and ing conditions of less than normal hot and norcold engine operation.

mal hot, and stop means to limit said throttle 9. Ina carburetor for supplying fuel to the opening movement to less than full open posiinduction system of an internal combustion ention while said engine is less than normal hot, gine, anair passageway through which air flows said stopmeans being inoperable when said eninto said induction system, ,a throttle operable gine is normal hot. I for regulating the flow of air and fuel through 6. In a carburetor for supplying fuel to the said air passageway into the induction system, induction system of an internal combustion enmeans for supplying fuel to said air passageway gine, an air passage, a throttle valve in said air including a nozzle arranged to discharge fuel passage and operable for regulating the flow of into said passageway upstream relative to said fuel and air through said air passage, into said throttle, and means for transmitting vacuum in induction system, means for delivering. fuel into said passageway from the downstream side of said passage comprising a plurality of fuel outsaid throttle to the end of said nozzle for effecting lets, said passageway being constructed and arthe delivery of fuel through said nozzle into said ranged so as to maintain substantially uniform air passageway on the upstream side of said pressures at all of said fuel outlets during sub- 0 throttle when said throttle is less than full open stantially full open throttle operation. during both hot and cold engine operation.

7. In a carburetor for an internal combustion 10. In a carburetor for supplying fuel to the engine, a main air passage, suction regulating induction system of an internal combustion enmeans comprising a throttle valve for controlling gine, an air passageway through which fuel and the suction in said main passage while said enair flow into said induction system, a throttle in gine is being started, and during engineoperasaid air passageway for regulating the flow of tion thereafter, and for controlling the flow of fuel andair through said passageway, means for fuel to said engine from said main passage during supplying fuel to said air passageway including said engine starting and operation, meansfor a nozzle adapted to discharge fuel into said pasdelivering fuel to said main passage in response sageway upstream relative to said throttle, and a to said suction therein, said means for delivering by-pass for transmitting the vacuum from the fuel comprisinga plurality of fuel outlets in said downstream side of saidthrottle to said nozzle, main passage, at least one of which is disposed said by-pass being operable at idle engine speeds downstream relative to said throttle, valve-type to effect the flow of fuel from said nozzle into fuel metering means operably disposed in said said passageway on the upstream side of-said fuel delivering means, connecting means operable throttle during both hot and cold engine operain response to actuating means, for adjusting tion.

said fuel metering means whereby fuel is supplied 11. A carburetor according to claim 10 wherein through said fuel delivering means to said main said nozzle is provided with a fuel conveying passage and said engine in accordance with the extension extending from said nozzle to a point requirements of said engine, said actuating means adjacent said throttle, said extension being concomprising said suction regulating means, and structed and arranged to convey liquid fuel in a other means, operable independently of said succontinuous stream from said nozzle onto said tion regulating means, for adjusting said fuel throttle at idle engine speeds. metering means so that fuel may be metered by r 12. Acarburetor according to claim 10 wherein said fuel metering means in quantities to suit said air passageway is constructed and arranged the temperature condition of said engine, said to maintain the pressure existing therein as reguoonnecting means being connected to said fuel lated by said throttle such that throttle positions metering means and said suction regulating in excess of idle effect the flow of atomized fuel means and said other means in such a manner as from said nozzle and from said by-pass into said to permit movement of said suction regulating 'air passageway.

means withoutcorresponding adjustment of said 13. In a carburetor for supplying fuel to the fuel metering means and so that said fuel meterinduction system of an internal combustion ening means may be adjusted independently of gine, an air passageway through which fuel and movement of said suction regulating means, Hair flow into said induction system, a throttle in dean-no 19" said air passageway forregulating the flow: of fuel and air therethrough, means for supplying fuel to said air passageway terminating in a main fuel outlet adapted tc-discharge fuel into said passageway on the upstreamside of said throttle at engine speeds in excess of idle engine speeds, and a by-passcommunicating at one end with said passageway on the downstream side of said throttle and at the other end thereof with the end of said nozzle for transmitting vacuum from downstream of said throttle to said main fuel outlet when said throttle is set for hot or for cold idle engine operation so as to thereby effect the flow of fuel from said main fuel outlet.

14. In a carburetor for supplying fuel tothe induction system ofan internal combustion engine, an air passageway through which fuel and air flow into said induction system, a throttle in said air passageway for regulating the flow: of fuel and air through said passageway, means for supplying fuel tosaid passageway including a nozzle arranged to discharge fuel into said passageway upstream relative to said throttle at engine speeds in excess of idle, said nozzle having a fuel conveying extension thereon projecting toward and in close proximity to said throttle, bypass means for transmitting a vacuum from the downstream side of said throttle to said nozzle when said throttle is set for hot or for cold idle engine speeds, said by-pass means being operable to effect the flow of fuel from said' nozzle onto said-fuel conveying extension at said idle engine speeds, said nozzle and extension thereon being constructed and arranged to convey liquid fuel in a continuous unbroken stream onto said throttle at idle engine speeds.

15; In a carburetor for supplying fuel to the: induction system of an internal combustion en gine, an air passageway through which fuel and: air flow into said induction system, a throttle insaid passageway for regulating the flow of fuel and air therethrough, means for supplying fuel: to said passageway including a nozzle adapted. to discharge atomized fuel into said passageway upstream relative to said throttle at engine speeds in excess of idle, said air passageway having a portion thereof constructed and arranged to maintain substantially constant the air-pressures existing in'said portion, at least during such conditions as are associated-with full open throttle, a by-pass communicating atone end withsaid portion of said air passageway; on the downstream side of said throttle and at the other end thereof with said nozzle for transmitting-vacuumfrom the downstream side of said throttle to said nozzle when said throttle is set for idle engine speeds during both hot and cold engine operation, said by-pass being operable-to effect the flow of fuel from said nozzle intosaid passageway upstream relative to said throttle at" idle engine speeds, said nozzle including a fuel conveying portion adapted toconvey acontinuous stream of liquid fuel from said nozzle ontosaid throttle at idle engine speeds, said throttle and said nozzle being located in said portion of said passageway, said throttle being so arranged relative to the end of said by-pass which" is on the downstream side of said throttleas to provide a vary". ing amount of vacuum at said: nozzle through said by-pass upon movement of said throttle from and toward idle positions thereof, thereby effecting a gradual transition from the. flow of: a. continuous liquid stream of fuelto the now of. atomized fuel from said nozzle, and vice versa.

comprising a nozzle 16. In a carburetor for supplying fuel to the induction system of an internal combustion en gine, an air passageway through which fuel and air flow into said induction. system, a throttle valve in said air passageway for regulating the flow of fuel: and air through: said passageway, and means for supplying fuel to-sa-id passageway upstream relative to said throttle valve, saidthrottle valve being adapted to extend across said passageway in. the closed position thereof and including at least a portion thereof corn-- prised of sintered metal, said sintered metal porticn providing a tortuous path for the flow of fuel therethrough.

17. In a carburetor for supplying fuel to the induction system: of an internal combustion en-- gine, an air passageway through which air and fuelfiow into said induction system, a throttle operable for regulating the flow of air and f-ueli through said passageway into said induction sys'-- tem, meansfor supplying fuel. to said passagewayincluding a main fuel supply system and an idle fuel supply system, valve means associated witheach' of said fuel supply systems for regulatingthe quantity of fuel supplied by said systems, thermostatic means operable response to en-- gi'ne temperature'and operably connected to'saiid valve means, vacuum means operable in response to the vacuum in said induction system and operably connected to said valve means, and: con-- necting meansoperably connecting said throttle to said valve means, said thermostatic means, said vacuum means, and said connecting means. each being arranged to operate said valvemeans. independently of operation of saidvalve' means by other of. said means, said thermostatic meansbeing capable of overruling said vacuum means and said connecting means.

18. In a. carburetor for supplying fuel to the induction system of an internal combustion engine, a passageway through which air and fuelflow into said induction system, a throttle valve in: said passageway for controlling the flow of and: fuel through said: passageway, means for supplying fuel tosaid: passageway, control means including a fuel control valve adapted to be posrtioned for regulating the supplying of f-"uel through said fuel supplying means during both cold and hot engineoperation, said control means being controlled inpart by said throttle valve, and means to prevent-opening movement ofsaidthrottle valve from changing the positioning of said fuel control valve from its coldoperating position to itshot operating position: when saidengine is cold or warming up;

19; In a carburetor adapted to supply fuel to the induction system of; an internal combustionengine, means providing: a passageway through which fuel and air flow to" said induction systema throttle in said air passageway for regulating the flow of fuel and air through said passageway including a throttlemember adapted to extend acrossv said air passageway when said throttle isclosed for idle engine operation; fuel supplying means including fuelmetering means, and fuel passage means adapted: todeliver substantially all: of the fuel supplied to said induction system during idle engine operationto the-upstream surface of said throttle member, said fuel passage means extending" intoclose: proximity with: said surface. of' said throttle member and being: constructed and arranged. toforma path. along: which fuel. is conveyed fromsaidmetering. means. onto said. throttle surface in an unbroken liquid; stream. having. a; uniform rate of flow substan-e tially the same as the rate of fuel flow through said metering means, said fuel passage means having a fuel outlet opening into said air pasengine, means which fuel and air flow to said induction system, a throttle in said air passageway for regulating said fuel outlet to said throttle, said fuel flow facilitating means extending into close proximity with the upstream surface of said throttle and forming an extension of said downwardly sloping fuel passage and having a surface exertidle engine operation.

21. A carburetor according to claim wherein said flow facilitating means projects toward said length of one drop of fuel.

22. A carburetor ccording to claim 21 wherein said throttle, at least at said one point, is composed of sintered metal.

23. In a carburetor for supplying fuel to the induction system of an internal combustion engine, an air passageway, a throttle valve in said air into which portion said air passageway upstream of said throttle and another of said outlets opening into said air passageway downstream of said throttle when passageway during off-idle engine operation, said air passageway having a restricted portion outlets open.

25. In a carburetor adapted to supply fuel to the induction system of an internal combustion engine, means providing a passageway through which fuel and air flow air passageway at full open throttle engine operation in response to absolute air pressure in said air passageway, said downstream outlet subjectanemia 23 said passage means including a surface at said fuel outlet producing a capillary action onthe flowing fuel during idle engin -operation to maintain the flowing fuel in. said unbroken liquid stream as such fuel flows from said fuel. outlet to the termination of. said passagemeans.

27.. In a carburetor adapted to supply fuel to the induction system of an internal combustion engine, means providing a passageway through which fuel and air flow to said induction. system, a throttle in said air passageway for regulating the flow of fuel and air through said passageway and including a throttle member: adapted to extend across said air passageway when. said throttle is closed. for idle engine operation, fuel supplying means including fuel. metering means, and fuel passage means extending from: said metering. means and having its. termination. in close proximity with the upstream surfacev of said throttle member and being adapted. to deliver substantially all of the fuel supplied to said induction system during idle engine operation to said upstream surface of. said" throttle mem er, said fuel passage means sloping: continuously downwardly and being constructed: and arranged. to form a path along which fuel: is conveyed: in an unbroken liquid stream having a uniform rate of flow substantially the same as. the rate. of fuel flow through said metering means during idle engine operation, the terminal: portion of said fuel passage means having a surface producing a capillary action on said stream: of liquid fuelso as to cause all of the fuel flowing through saidpassage means during idle engine operationto flow to the said termination of said passage means in said unbroken liquid. stream.

28. In a carburetor adapted to supply fuel to the induction system of: an internal combustion engine; means providing a passageway" through. which fuel and air flow to said induction system,. a throttle in said air passageway for regulating the flow of fuel and air through said passageway and including a throttle member'adapted' to extend across said air passageway when: said throttle is closed for idle engine operation, fuel.

supplying means including fuel metering means having an outlet from which only liquid fuel is discharged fuel passage means extending from said metering means outlet, said metering means including an air inlet opening into=said1 passage means, said passage means-havinga. fuel. outlet therefrom opening into said' passageway upstream of said throttle member and through which outlet air and fuel are. discharged during full open throttle engine operation, saidpassage means being adapted to convey a streamof liquid fuel from metering means outlet to: said fuel outlet during idle engine operation, said passagemeans having a cross-sectional area substantially greater than the cross-sectional area of said stream of fuel which is conveyed by said passage means during said idle engine operation and sloping downwardly continuously from said metering means outlet to said fuel outlet so as to form a path adapted to cause fuel toflow along said passage means to said fueloutlet during idle engine operation in an unbroken liquid stream having a uniform rate of" fiow sub stantially the same as the rate of fuel flow through said metering means outlet, said passage means having its termination in close proximity to the upstream surface of said throttle member and including a fuel flow facilitating' means in the form of a surface producing a capillary action on said unbroken stream of liquid fuel at 24. said outlet during idle engine operation so as to cause all of such fuel to flow in said unbroken liquid stream and atsaid uniform rate of flow to said termination: of said passage means.

29. A carburetor according to claim 28 wherein said termination of said passage means is-spaced from onepoint on said upstream throttle surface with a spacing of lessthan the length of one drop of fuel.

30'. A; carburetor aceording to claim 29 wherein said. throttle member at said one point is composedof sintered metal;

31. In a carburetor. adapted to supply fuel. and to an internal combustion engine; fuel and air: mixture supplying; means including a passageway, fuel conveying: meansavalvmtype throttle means, and valve-type vacuum modifying means; said passageway for-sing a. part. of the induction system of said engine; said conveying means having a fuel outlet therefrom for: conveying fuel to: said passageway in response to the vacuum therein; said: throttle mean being disposed insaid passageway and operable for controlling in. part the quantity of air flowing. through said passageway, thequantity of fuel supplied through said" conveying means and the amount of vacuum in said passageway downstream of said throttle means during cold engine starting and operation; said vacuum modifying means. being operable for controlling in part the amount of vacuum in said conveying means thereby the amount of fuel supplied by said conveying means during: said cold engine starting and operation; said conveying means being adapted to convey an amount of fuel adequate for. said cold starting and operation, the same saidfuel conveying means: being adapted to convey an. amount of fuel adequate for hot engine starting and operation; said carburetor including throttle operating means, a plurality of throttle stop means, other means? connecting. means; said stop-meansbeingoperable in part responsive to said other means and eooperable with said. throttle operating means; a first of said stop means providing a full open position. of. saidpassageway during hot engineoperation; a second of said step means providing a position of said throttle means in which said passageway is opened tov an extent. to provide a predetermined amount of vacuum for cold starting of said engine; a third one. of said stop means providing a position of. said throttle. means at which said pas sageway is opened to an extent less than as providedby saidflrst stopmeans to limit the amount of. vacuum. for cold engin operation; said other -means being operable independently of. said throttle-operating means. for adjusting said supplying means whereby the latter will provide fuel and air in. proportions and quantities suited to the temperature condition of said engine; said.

connecting means. connecting said supplying means, saidthrottle operating means, said second and. third step means and said other. means in such r anner as topermit substantial movement of said throttle operating means without corresponding adjustment of said vacuum modifying means", and" so that said vacuum modifying means may be adjusted by' said other means independently of movement of said throttle operating means, whereby said supplying means as adjusted by said other means to provid'e said adequate cold engine fuel. supply remains so adjusted during substantial movement, of said throttle operating means.

(References on following page) References Cited in the file of this patent Number UNITED STATES PATENTS Name Date Stokes Dec. 18, 1934 Cole July 1, 1913 Wetterhahn Oct. 5, 1915 Robbins Sept. 5, 1916 Grant Jan. 6, 1920 Hodges Apr. 25, 1922 Merellini et a1 Oct. 7, 1924 Chambers Mar. 22, 1932 Viel Oct. 3, 1933 Number 26 Name Date Wynne et a1 Oct. 30, 1934 Leibing Feb. 12, 1935 Mallory July 9, 1935 Ball et a1. Dec. 17, 1935 Chandler Mar. 31, 1936 Udale Mar. 31, 1936 Scott May 18, 1937 Hunt Dec. 21, 1937 CoX et a1. July 26, 1938 Emerson Aug. 16, 1938 Jorgensen et a1. June 19, 1951 

